Ron dismissed the warning, she says.

"He said, 'Ma, I'll be fine," says Wunderlich, over the phone, through a torrent of tears. "Don't worry about me."

Saturday evening, she received a call from one of her son's best friends.

There had been an accident. Ron went in the water about 28 miles west of Anna Maria Island to spear some of the amberjack swarming around the boat and never resurfaced. After search most of the day, the Coast Guard called off the active search Saturday night.

Though there is no conclusive proof, Wunderlich believes her son is dead.

"He was born a water baby and he died a water baby," Wunderlich says.

Ron Wunderlich was free diving when he failed to resurface at about 9:45 a.m. Saturday, according to the Coast Guard.

Unlike scuba divers, free divers rely on stored breath.

He was wearing only shorts and a weight belt at the time, according to the Coast Guard, which deployed a 25-foot rescue boat and an HH60 Jayhawk helicopter to search for Wunderlich. The Florida Fish and Wildlife Conservation Commission, as well as Sarasota Police divers also assisted, but could not find Wunderlich.

Free diving requires a great deal of training and discipline, says Mark Rush, a Sarasota-based diving instructor who is certified to dive both scuba and free dive.